Automatic swimming pool cleaners of the type that move about the underwater surfaces of a swimming pool are driven by many different kinds of systems. A variety of different pool-cleaner devices in one way or another harness the flow of water, as it is drawn or pushed through the pool cleaner by the pumping action of a remote pump for debris collection purposes.
The present disclosure is applicable to both pressure and suction cleaners. An example of a suction (negative pressure) cleaner is disclosed in commonly-owned U.S. Pat. No. 6,854,148 (Rief et al.), entire contents of which are incorporated herein by reference. An example of a pressure cleaner is disclosed in commonly-owned U.S. Pat. No. 6,782,578 (Rief et al.), entire contents of which are incorporated herein by reference.
Referring to FIGS. 1-4, a suction cleaner 100 of the prior art for use in a swimming pool is disclosed. The suction cleaner 100 can be in accordance with U.S. Pat. No. 5,105,496 to Gray, Jr. et al. and U.S. Pat. No. 4,536,908 to Raubenheimer, which are incorporated herein by reference in their entirety and which are discussed in part in this Background of the Present Disclosure section. FIG. 1 is a perspective view of the suction cleaner 100, which includes a housing 102, a rear inlet 104, walking pods 106, and a cone gear 108 that engages a suction hose 17. FIG. 2 is a partial sectional view of the suction cleaner of FIG. 1 taken along line 2-2 of FIG. 1 showing a prior art rocker arm, rocker arm locomotion system, and steering system. Referring to FIG. 2, there is shown the primary and secondary fluid flow paths for a suction device for cleaning swimming pools. Water enters a primary flow path at the primary fluid inlet 112. It meets the fluid from one of the secondary fluid outlets 114, continues past the primary turbine 116, and joins with the other secondary fluid outlet 118. The primary turbine 116 is mounted on a shaft 120 having eccentric cams 122. As the primary turbine 116 turns, it turns the rocker arms 124 which are on pivots 126 and which extend out to walking pods 106 which cause the suction device 100 to move forward. The fluid from the primary and secondary flow paths is discharged through the cone gear 108 (e.g., the primary fluid outlet) which is connected to the suction hose 110 as shown in FIG. 1.
Continuing with a discussion of the prior art, in the secondary fluid flow paths, fluid enters at the secondary fluid inlet 130, which extends across the rear inlet, passing through a cleaner steering gear assembly 131 that includes a pair of secondary turbines 132, 134. The first secondary turbine 132 is housed within a gearbox 136. The second secondary turbine 134 is housed within a chamber 137. The secondary turbines 132, 134 work together to intermittently apply torque about the axis of the suction hose 110. The top secondary turbine 134 turns the suction hose 110 thereby providing the torque. The bottom secondary turbine 132 provides the change in direction of the torque applied by the top secondary turbine 134 by causing a reverse in the rotation of the top secondary turbine 134. This operation is similar to that described in U.S. Pat. No. 4,521,933 to Raubenheimer, which is incorporated herein by reference in its entirety.
The fluid outlet from the bottom secondary turbine 132 passes through the integral screen 138 and out the secondary fluid outlet 114 at the inlet of the primary turbine 116. The fluid outlet from the top secondary turbine 134 passes through internal screen 140 and out the secondary outlet 118 at the top of the primary turbine 116.
A captured screw 142 mounted in a mounting 144 rigidly positions and secures a removable door 146. Guide channels 148 fixedly position the filter screen 138 at the discharge of the bottom secondary turbine 132 thereby preventing back wash from the primary turbine inlet from entering the secondary fluid outlet 114.
Continuing with a discussion of the prior art, FIG. 3 shows a cross section of the suction cleaning device 100 ready for use. The location of the removable door 146 is outlined and is shown to be positioned over the entrance to the primary flow path and the primary turbine inlet. The turbine 116 is housed in the housing 102 and secured to the housing walls 149 by means of bearings 150 on the turbine shaft 120. It will be seen that if water flows from the primary fluid inlet 112 to cone gear 108 (e.g., the primary fluid outlet), the turbine 116 will rotate. Also on the shaft 120 are the eccentric cams 122 which are between rocker arm bearings 152 fitted to the rocker arms 124. The eccentric cams 122 are 180 degrees out of phase with each other. As the shaft 120 rotates, the rocker arms 124 will rock back and forth about the pivots 126.
Continuing with a discussion of the prior art, FIG. 4 is a partial sectional view of the suction cleaner of FIG. 1 taken along line 3-3 of FIG. 2 showing the prior art rocker arms of the locomotion system with the turbine removed. Further, FIG. 4 shows a cross-section of the suction cleaning device 100 without the turbine 116, and showing the rocker arms 124 in greater detail. As shown in FIGS. 2 and 4, each rocker arm 124 includes a body 154 with two arms 156 extending therefrom. Each of the two legs 156 of the rocker arms 124 includes a respective rocker arm bearing 152, as discussed above. Each rocker arm 124 is integrated with a walking pod 106 to which it is connected by the pivot 126. The pivot 126 can include a square end where it connects with the walking pod 106 such that rotation of the pivots 126 is imparted to the walking pods 106. The inner ends 158 of the pivots 126 are secured for rotation in a split bearing 160 on the housing 102.
Continuing with a discussion of the prior art, as the turbine 116 rotates, the turbine shaft 120 and eccentric cams 122 also rotate, with the turbine shaft 120 rotating within the bearings 150 that are secured to the housing 149. As the eccentric cams 122 respectively rotate between and engage a pair of rocker arm bearings 152, which are secured to a respective rocker arm 124, they push the rocker arms 124 in opposite directions. That is, because of the eccentric cams 122 are 180 degrees out of phase with one another, one of the eccentric cams 122 will push the rocker arm 124 that it is engaged with rearward (e.g., clockwise rotation about the pivot 126), while the a second of the eccentric cams 122 will push the rocker arm 124 that it is engaged with forward (e.g., counter-clockwise rotation about the pivot 126). Accordingly, continued rotation of the turbine 116 causes the rocker arms 124 to rock back and forth. As the rocker arms 124 rock, their movements are imparted to the walking pods 106. The result is that as the turbine 116 rotates, the walking pods 106 rock and the whole device moves forward.
However, the rocker arms 124 of the prior art and four associated bearings 150 (two bearings per arm) are vulnerable to extreme wear and tear due to fine sand and debris. Contact shock between the bearings 150 and the eccentric cams 122 of the turbine 116 are also adverse to the bearings, resulting in replacement that can be costly to replace. Additionally, the turbine 116 has a ridged fixed shape and is also supported by two bearings on either rend that also suffer from wear and tear in a short period of time, which can be costly. Generally, there is an excessive clearance between the bearings 152 of the rocker arms 124 and the turbine eccentric cams 122, such that when the eccentric cams 122 rotate contact between the eccentric cams 122 and the bearings 152 is lost for a period of time, resulting in a hammer or knocking effect to occur when the eccentric cams 122 come back into contact with the bearings 152. This hammer effect can result in damage to the bearings 152 and the eccentric cams 122.
Continuing with a discussion of the prior art, as previously discussed in connection with FIG. 2, the housing includes a gearbox 136 housing a first secondary turbine 132, and a chamber 137 housing a second secondary turbine 134. Two passages 162 port into the chamber 137 and the interior space 164 of the housing. The interior space 164 is in fluidic communication with the passages 162 and the rear inlet 104, such that fluid can flow through the rear inlet 104, into the interior space 164 and across the passages 162. The ports 162 to the chamber 137 are controlled by a valve plate 166, which is discussed in greater detail below.
Continuing with a discussion of the prior art, the cleaner steering gear assembly 131 of the prior art includes the cone gear 108 that has a large gear wheel 168, and a drive pinion 174. The drive pinion 174 is connected to a gear 176 by a shaft 178. The cleaner 100 further includes the first and second secondary turbines 132, 134, the valve plate 166 connected to a gear 170 by a shaft 172, and a gear reduction stack 180. The first secondary turbine 132 includes a pinion 182 that meshes with an input gear to the gear reduction stack 180, all of which is located in the gearbox 136. The gear reduction stack 180 includes an output gear that meshes with the gear 170 connected to the shaft 172 and valve plate 166. Fluid that flows through the rear inlet 104 and into the interior space 164 can flow across the passages 162 into the chamber 137 and across gearbox openings 184 and into the gearbox 136. Fluid flowing into the gearbox 136 rotates the first secondary turbine 132 which outputs to the gear reduction stack 180, which in turn outputs to the gear 170 causing the valve plate 166 to rotate. As the first secondary turbine 132 rotates the valve plate 166, the valve plate 166 alternately covers and uncovers the ports 162 with relatively long periods when both parts are covered. When one of the ports 162 is covered fluid flowing through the open port 162 will cause the second secondary gear 134 to rotate clockwise, while when the other of the ports 162 is covered fluid flowing through the other open port 162 will cause the second secondary turbine 134 to rotate counter-clockwise. When both ports 162 are covered the second secondary turbine 134 does not spin. Accordingly, alternately covering and uncovering the ports 162 causes the second secondary turbine 134 to change direction of rotation.
Continuing with a discussion of the prior art, the second secondary turbine 134 includes an output pinion 186 that meshes with the gear 176 connected to the drive pinion 174 by the shaft 178. The drive pinion 174 meshes with the large gear wheel 168 of the cone gear 108. Accordingly, as the second secondary turbine 134 rotates, the pinion 186 rotates the gear 176, causing the drive pinion 174 to rotate. In turn, the drive pinion 174 rotationally drives the large gear wheel 168 thus applying a high slow speed torque to the cone gear 108. Rotation of the second secondary turbine 134 in a clockwise direction results in clockwise rotation of the cone gear 108, while counter-clockwise rotation of the second secondary turbine 134 results in counter-clockwise rotation of the cone gear 108.
Continuing with a discussion of the prior art, as one of the ports 162 are uncovered, the second secondary turbine 134 applies a torque to the cone gear 108 which in use is attached to the suction hose 110. The hose 110 will resist the turning movement and the net effect is that the whole cleaner 100 turns around the axis of the cone gear 108. When the then open port is closed, the device will be facing a random new direction usually different from its original direction. Of course, the running of the second secondary turbine 134 will constantly tend to move the cleaner 100 in its forward direction at any given time so that in turn a somewhat spiral movement will take place (when one of the ports 162 are open).